Bioenergy Crops Energy crops could cover energy demand in surplus agricultural lands

Energy crops could cover energy demand in surplus agricultural lands

A brand new study (2013) found that the projected energy demand (2035) in developing countries, can be covered with energy crops in surplus agricultural lands, then not competing with food production. The study, from the Department of Energy Technology, at Aalto University School of Engineering (Finland) was accepted by the sound scienfitc journal Renewable and Sustainable Energy Reviews.

The authors did first an extensive literature review considering current status on land availability, land use pattern, crops and energy production and their present and projected demands. Historical trends in land use changes, crop yields, per capita land use were also reviewed from statistical database and literature sources. In the second part, a set of assumptions were made based on the information and insight gained from the reviewed literature to determine the extents of land availability for growing selected energy crops to meet the projected demands.

The article, mentions that a FAO report ( ) estimates that total land area under crop production in 2010 was 1545 Mha and would be 1645 Mha in 2050. Same FAO study suggested that although few countries have reached or are about to reach the limits of their available land for agriculture, at the global level there is still sufficient land resources to feed the world’s population for the foreseeable future in line with the estimated yield growth.

Perennial plants can occupy pastures and degraded lands

The study focus all the assessment in perennial species and agricultural residues mostly. Regarding energy crop, this publication focused on scenario building with jatropha, willow, poplar, switchgrass and miscanthus.

The study considers different crops including miscanthus, switchgrass and willows in meadows, pastures and surplus lands

Land use changes may exist, but there is enough land available for perennials.

The article pointed clearly that the projected population in the developing countries are expected to be 5858 million in 2035, and they require 1933 Mt of cereal crop products and 2580 Mt of other crops (roots and tubers, pulses, sugar crops, and oil crops) considering consumption of 3302 kcal (13.8 MJ) per capita per day in 2035. Although there is still considerable room for yield improvements in developing countries, the authours assumed the yields are based on the current modern agricultural practices. Further improvement of crop yields will significantly decrease the land requirement for food and feeds. Moreover, FAO estimates, one-third of the food produced is wasted during harvesting and transportation in developing countries.

The three land-use categories, namely arable land, meadows and pastures land, and forest land are the contributors to form increasing croplands. The total 2.782 Gha cropland will be constituted from combination of existing cropland, and upgraded meadows and pastures lands in 2035. We estimate that 1.105 Gha of cropland will be required for crop production and the remaining 1.67 Gha of cropland will remain surplus for energy crop productions. The authors also extend this study to a case where surplus cropland is constituted only from upgradation of part of permanent meadows and pastures land, and this cropland is afforested by energy crops . The available lands for crop production in each of the four continental regions (developing countries) are shown in the table below.

The study concludes that There are sufficient land resources to grow food and other plant products to feed the population and meet other needs in developing countries.

The energy crops are assumed to be grown only on surplus cropland, to avoid competition with food production. The studied energy crops are found suitable for growing in the tropical and sub-tropical developing countries, and their corresponding land scenarios are evaluated.

The land areas that should be available for energy biomass production in 2035 are 0.45 Gha and 0.95 Gha for miscanthus and switchgrass production scenario respectively while the surplus cropland beyond food and feed production is projected as1.67 Gha. The available lands are clearly more than the land required for all energy crops scenario in Africa, and Latin American regions. Asian regions are short of surplus croplands, which are required to grow energy crops to deliver the projected energy demand.

The study concludes that there are sufficient land resources to grow food and other plant products to feed the population and meet other needs in developing countries including fiber and energy crops . The production of energy crops in the surplus agricultural lands can overall meet projected primary energy demand through 2035 in the developing countries considering four energy crop scenarios. The land availability and energy demand coincide for African and Latin American countries, which reduce the transportation risks of biomass. Asia, however, lags behind in providing surplus cropland required to deliver the projected energy demand.

Agroforestry and combinations of food and lignocellulosic crops already demonstrated have not being considerd.

The cropland can be surplus from cropland expansion, yield improvements or grassland upgradation. The dedicated energy crops can be grown in the tropical climate condition what actually the case in developing regions. The practice of growing energy crops are not wide spread in the developing counties, this might need serious effort from the governments, policy makers, and other stockholders to lay support for their dissemination. The productivity of crops in sub-Saharan Africa is very low, usually 1 t/ha, whereas in developed countries, it is 5 t/ha or more; therefore there is still big room to increase production without land expansion.

The study is basically very much complete and the only aspect to remark is that authors only considered 4 species when there is a broad large group of possible lignocellulosic energy crops including shrubs, short rotation forestry and perennial grasses in tropical, subtropical and temperate areas. Additionally the study does not consider agroforestry, double cropping systems, by-products or any combination in rotations that would eventually increase the potential land availability without food disruptions.

The published article can be obtained here.